1. Technical Field
The present disclosure relates to imaging apparatuses, such as cameras, and imaging systems that include the imaging apparatuses.
2. Description of the Related Art
In recent years, image sensing cameras have been being researched and developed. For example, an image of an object is obtained by imaging under a plurality of imaging conditions, such as the polarization condition of light used in imaging and the wavelength of the light. The image is then analyzed and information on the object is obtained.
Examples of conventional image sensing cameras include a multiband camera, which can obtain a two-dimensional spectral image of an object through a single instance of imaging. Such a multiband camera is disclosed, for example, in U.S. Pat. No. 7,433,042 and Japanese Patent No. 5418392. In addition, Japanese Patent No. 5001471 discloses an imaging apparatus that includes a spectral filter array disposed at a position of an entrance pupil of an imaging optical system and a microlens array disposed in the vicinity of an image sensor. Light rays that have been dispersed by the spectral filter array are guided to different pixels by the microlens array, and thus a desired spectral image can be obtained.
Hereinafter, an exemplary configuration of a conventional multiband camera will be described.
The multiband camera disclosed in Japanese Patent No. 5418932 divides the wavelength range of light to be used to image an object into four or more mutually different wavelength bands and images the object in these wavelength bands. The multiband camera includes a band-pass filter array disposed at a position of a pupil of an optical system, a microlens array, a photoelectric conversion element constituted by a plurality of pixels that are arrayed two-dimensionally, and a measurement unit that measures the spectral intensity of a light beam from the object.
The band-pass filter array includes four or more band-pass filters that transmit light in respective four or more divided wavelength bands. The photoelectric conversion element is disposed around the focal point of the microlens array and at a position where the photoelectric conversion element is conjugate with the band-pass filter array or in the vicinity of such a position. Light beams that have passed through the band-pass filter array are then guided by the microlens array to the plurality of pixels that are arrayed two-dimensionally. The measurement unit measures the spectral intensity of the light beams from the object on the basis of signals outputted from the plurality of pixels corresponding to the respective band-pass filters in the band-pass filter array.